Conventionally, LCDs (Liquid Crystal Displays) and OLED (Organic Light Emitting Diode) displays are manufactured as follows. A plurality of displays are manufactured at the same time on a large glass substrate, and then the glass substrate is cut and separated into the plurality of displays individually. In general, the glass substrate is cut by a method using a scribe cutter or a method using laser light irradiation.
An LCD and an OLED display are each generally have a structure including two glass substrates bonded together. In the above-described cutting step, the two glass substrates are cut together. However, in the state where the two glass substrates are cut in this manner, terminal portions on one of the two glass substrate, namely, an array substrate having a display circuit and the like formed thereon, are covered with the other glass substrate. Therefore, generally, after the two glass substrates are cut together, another step of cutting only the glass substrate not having the terminal portions thereon to expose the terminal portions is performed.
Examples of known technologies for selectively cutting only one of the two substrates bonded together are described in Japanese Laid-Open Patent Publications Nos. 2004-126054 and 2009-98425. According to the technologies disclosed in these publications, each of liquid crystal display devices individually separated is irradiated with laser light to cut a part of one of the two substrates, namely, a counter substrate, to expose the terminal portion on the other substrate, namely, the array substrate. Both of the publications disclose a technology for providing a metal film below a position along which the counter substrate is to be cut, so that the laser light does not hit the array substrate, which is formed of glass.
With the technologies disclosed in the above-mentioned two publications, the step of exposing the terminal portion needs to be performed after the glass substrates are separated into the individual liquid crystal display devices. Namely, the step of laser light irradiation needs to be performed on individual liquid crystal display devices separated from each other from the state of being provided between the large glass substrates. This is a factor decreasing the throughput in the mass-production of the liquid crystal display devices.